noun 1. a unit of area measurement equal to a square measuring one inch on each side; 6.452 square centimeters. 2 , sq. in. Abbreviation: in.
- Square john
noun 1. a unit of area measurement equal to a square measuring one kilometer on each side. 2 , sq. km. Abbreviation: km.
adjective, Electronics. 1. of or relating to an electronic circuit or device that produces an output voltage proportional to the square of its input voltage over the range of input voltages for which it is designed to function: square-law detector.